It's the Space Boffins' most controversial episode yet, as Don Goldsmith talks about his new book written with Astronomer Royal Martin Rees - The End of Astronauts and why robots are the future. Also, we visit one of the cleanrooms at Airbus in Stevenage to see the new Biomass satellite to measure the carbon locked in the world's forests. Plus author Kevin Cook talks about his book, The Burning Blue, on Christa McAuliffe and the Challenger disaster. Like this podcast? Please help us by supporting the Naked Scientists